Effect of the trendelenberg position on spinal anaesthesia with hyperbaric bupivacaine

In a double-blind study, the effect of the Trendelenberg position was compared with the supine, in 20 patients following intrathecal injection of 3 ml of 0.5% bupivacaine in 8% glucose. All patients had blocks suitable for abdominal surgery. Although the mean spread was greater in those patients titled head-down, this was not statistically significant. The variation of the spread around the mean was greater in the head-down group, and blocks extended into the cervical region in two patients. There were no differences in motor block, duration or cardiovascular changes between the groups. It is concluded that the trendelenberg position is not necessary to ensure spread of local anaesthetic solution into the mid thoracic region for abdominal surgery.